Valve-timer for internal-combustion engines.



T.'W'. MORGAN.

VALVE TIMER FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DEC. 30, I912.

Patented Aug. 17, 1915.

2 SHEETSSHEET 1.

THOMAS W. MORGAN, OF WATERLOO, IOWA, ASSIGNOR T0 WILBUR W. MARSH, OF

. WATEBLOO, IOWA.

VALVE-TIMER FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Aug. 17, 1915.

' Application filed December 30, 1912. Serial No. 739,193.

To all whom it may concern:

Be it known that I, THoMAs W. MORGAN, a citizen of the United States,and a resident of Waterloo, in the county of Blackhawk and State ofIowa, have invented certain new and useful Improvements in Valve- Timersfor Internal-Combustion Engines, of which the following is a full,clear, and exact specification.

My invention relates to internal combustion engines, and has moreparticular referonce to improvements in valve timers therefor.

The primary object of my invention is to provide an improved valve timerfor reversible internal combustion engines.

A. further object of my invention is to provide an improved mechanism ofthis character which will be simple, durable and reliable inconstruction, inexpensive to manufacture, and effective and elficient inoperation.

Other objects of my invention will appear hereinafter.

My invention consists in the features of novelty exemplified in theconstruction,

combination and arrangement of parts herein described, and shown in theaccompanying drawings which illustrate one embodiment of my invention,and more particularly pointed out in the appended claims.

i In the drawings, Figure 1 is an end elevation of a single cylinderinternal combustion engine embodying my invention. Fig. 2 is a view ofsaid engine in elevation at 'right angles to that of Fig. 1. Fig. 3 isan enlarged elevation of the cam and gear mechanism. Fig. 4 is asectional view on the line 44 of Fig. 3. Fig. 5is a fragmentary sectionon line 5-5 of Fig. 3. Fig. 6 is a viewof the cams and valve actuatingmechanism embodying my invention as a plied to a four-cylinder engine;and Fig. is a lefthand end view of the mechanism shown in Fig. 6.

My invention concerns more particularly to the valve timing andoperating mechanism of internal combustion engines, and for the sake ofsimplicity of illustration, I have shown in-the drawings a singlecylinder engine of the type in which only the ex haust valve mechanismis operated by cams driven from the crank shaft. It will be obvious,however, to one skilled in the art, after having obtained anunderstanding of my invention from the disclosures herein made, that myinvention may, without departing from the scope and spirit thereof, beapplied to other types of internal coinbustion engines, such forinstance, as the type wherein both the exhaust and intake v sages. bywhich the gas is conveyed to the cylinder and the exhaust conveyedtherefrom for the reason that these parts and mechanisms may be of anyusual or standard construction well known in the art. Suilice to saythat the rod 1 which reciprocates vertically in'the bearing 2 on thehead of the cylinder in the usual way is representative of the valvemechanism of internal combustion engines. The rod 1 moves verticallydownward in its bearing as is well known to open the exhaust port andallow theescape of exhaust gases and moves upward in its bearing toclosesaid port. These rods, in engines of the type of which that shown in thedrawing is representative, are constantly pressed upward by the spring 3to hold the exhaust port closed, spring 3 bev ing disposed between thehead of the cylinder and a collar 4 on the rod. At the proper time forthe port to be opened the walking beam 5 is operated to depress the rod1 against the action of its spring 3. This walking beam may be of thetype used in connection with single cylinder internal combustionengines. It consists of a substantially horizontally disposed levercentrally pivoted upon an upstanding lug 6 cast on the cylinder head, asshown clearly in Figs. 1, 2, 8 and 9. The arm 7 of this walking beam isarranged in position to act upon the upper end of the rod 1 and depressit at the proper time. A screw memher 8 is generally provided foradjusting the apparatus 14 is positioned in such relation to the valveactuating rodll that it may be actuated thereby, an arm 15 being mountedupon the member 11 for this purpose. As is well known these mechanismsare so timed in relation to each other that the spark will occur atproper intervals. The sparking apparatus needs no further explanation.

It is generally well known that internal combustion engines may be runin either direction of rotation, depending upon the direction in whichthey are initially started. The opening and closing of the valve,however, must bear a definite time relation to the operation of theengine. In other words, the valves open and close at certain points inthe cycle of operation of the piston and these points, as is well known,change in accordance with the direction of rotation of the engine. Inaccordance with my invention I provide valve timing mechanism whichtimes the valves properly relatively to the direction in which it isdesired to run the engine without the necessity of having to disassembleand reassemble the parts or mechanism. As a simple way of carrying outmy invention, I provide a pinion spur gear 20 on the crank shaft A whichgear is arranged to drive a larger spur gear 21 mounted upon a suitablestud shaft 22 projecting from the side-of the crank case A of theengine. The centers of the crank shaft A stud shaft A and the valveactuating member 11 being preferably positioned in vertical alinement.The large gear 21 is free to rotate on the stud shaft. Adjacent one faceof the large gear 21 I provide a cam 23. This cam is rotatably mountedupon the hub of the gear 21, as shown in Figs. 4 and 5, so that both camand gear may be independently rotated. The cam 23 when it rotates,reciprocates the valve actuating member 11. The lower end of the member11 carries a small anti-friction roller 25 which engages and runs on thesurface of the cam 23. During the operation of the engine it will beseen that the cam 23 must occupy such a position relatively to thepiston of the engine that the exhaust valve will be operated at theproper time. The relative position of the cam for one direction ofrotation of the engine will not, as is readily seen, serve for the otherdirection of rotationand consequently the cam must be relativelyshifted, and for this reason, asbefore intimated, the cam may be rotatedrelatively to the gear 21. Since, however, the cam after beingrota-tively shifted to-itsproper position must be maintained in positionI provide a connection be tween the gear 21' and the cam which permitsof these conditions. In the structure shown this connection ispreferably formed by two small spring pressed pins 30 projecting fromthe inner face 31 of the cam and adapted to enter small depressions inthe adjacent face of the large gear 21. These small pins are preferablyhollow (Figs. 3, 4, 5 and 6) for the reception of the small spiralsprings-32. The pins are 'mounted to slide in suitable bores or holes inthe face of the cam 21. The springs 32 are held in place by theremovable screw caps 35 and tend to yieldingly force the member or pins33 against the face of the gear 21. The ends of these pins arepreferably cone-shaped so that when a centain amount of relativerotative force is applied to the cam the small pins will yield and rideout of the depressions in the face of the gear 21. I provide two sets ofdepressions 36 for the spring pressed pins. The two depressions in eachset are placed in the proper relative position corresponding to thedirections of rotation of the engine. For instance: in Figs. 1 and 3 thecam is shown in the proper relative position corresponding to thedirection of rotation of the crank shaft indicated by the arrow X. (Fig.1), while the dotted outline (Fig. 1) of the cam shows it in properposition corresponding to the direction of rotation of the crank shaftindicated by the arrow Y. It will thusbe seen that by simply shiftingthe cam rotatably a slight amount it may be conveniently and properlypositioned to actuate the valve member 11 and the valve mechanism inproper timed relation to the other parts of the engine depending uponthe direction of rotation of the engine. This cam, if desired, maybeshifted manually before the engine is started, but I prefer that thisoperation take place automaticallv. For this reason I so proportion theparts that during the initial movement of the crank shaft and largergear in either direction of rotation the cam will be automaticallyshifted to the proper position corresponding to that direction ofrotation, and

the engine may be run continually in that direction without any furthernecessity of adjusting the cam or other operating part. This automaticoperation may be simply accomplished by arranging the valve actuatingmember 11 and the other parts of the valve mechanism in such manner thatthey will offer suflicient resistance to the turning of the cam to shiftit from one set of depressions to the other. In order, however,

to prevent further relative rotation of the cam after it has beenproperly shifted, as above described, I provide a curved slot 38 1n thelarge gear 21. In thisslot a bolt 39 is adapted to operate. This boltis, as shown in Fig. 5, inserted through a slot in the gear and screwedinto the cam 23. The ends of the slot, co-acting with the bolt, serve aslimit stops corresponding to the two positions of the cam, and henceafter the cam has been shifted from one of its positions to the otherthe bolt and slot prevent. further rotation thereof during thecontinuous operation of the engine. This bolt also is intended to serveas a locking means for locking the cam and gear together in the eventthat it is'desired to run the engine for any extended length of time inone direction. In other words, after the cam has been shifted eitherautomatically or manually, as the case may be, to the positioncorresponding to the direction of rotation of the engine, the bolt maybe tightened to clamp the cam firmly to the gear, and the engine maythen be started and stopped as many times as desired without danger ofthe adjustment being disturbed.

As before intimated, my invention is equally as applicable to two orfour cylinder engines, or engines embodying commercially practicablenumber of cylinders, and in. order that this may be clearly understood,I have illustrated my invention as applied to a four cylinder engine. Iconsider it unnecessary to illustrate a complete engine in thisconnection and for this reason I have, in Figs. (3 and 7, illustrated aportion of the crank shaft and the cam shaft together with theinterconnected driving mechanism. In this construction the cam shaft isconsiderably longer than the cam shaft 22 for the single cylinderengine, so that it may extend in operative relation to the valveactuating members 11 of the severalv cylinders. This shaft carries fourcams 23 angularly arranged around the cam; shaft 22 so as to operate thevalve rods 11in their proper se-,

qnence. It would be impracticable and inconvenient, although possible,to provide a cam and gear connectlon for each of the .valve actuatingmembers 1'1, and for this reason I provide a common arm or member 45adjacent the gear 21. This arm is keyed or otherwise securely fastenedto the cam shaft 22 but the gear 21 is rotatable thereon. Only onespring pressed pin 32 instead of two as in Fig. 1, is necessary, henceit is only necessary to provide one depression 36 for each of the tworelative positions of the arm 45 with respect to the direction ofrotation of the parts. The arm 45 has a similar bolt and slot connection39 and 3 8 respectively, with the'large gear. This construction performsthe same functions as previously described in connection with the singlecylinder engine. Thus the four cams can be automatically positioned as agroup with respect to the direction of rotation instead of an individualmechanism for each of the four cams.

It will thus be seen that my invention provides a very simple andeffective means for timing the valve mechanism with respect to thedirection of rotation. When the mechanism is arranged to operateautomatically, as previously described, the initial movement of theparts in either direction when cranking the engine automatically shiftsthe cams and times them with respect to the particular direction ofrotation of the engine, and no further manipulation or adjustment isrequired. The engine may then continue to operate in that direction ofrotation with its valve mechanism correspondingly timed When it is to bereversed, the act of cranking in the reverse direction automaticallyshifts the cam accordingly.

What I claim is:

'1. Thecombination with the cam shaft of an internal combustion motor,of a gear wheel mounted thereon and driven from the engine shaft, saidgear wheel being provided with an arcuate slot concentric to the camshaft, a cam journaled on the shaft at one side of said gear wheel, apin on said cam movable len thwise of said slot, a looking dog for holing the cam with its said pin at either end ofthe slot, and a spring foryieldingly maintainingthe said locking dog and cam in holding position.

2. The combination with a cam shaft of an internal combustion motor, ofa gear wheel mounted thereon and driven from'the engine shaft, said gearwheel being provided With an arcuate slot concentric to the cam shaft, acam journaled on the cam shaft in proximity to one side of said gearwheel, a pin mounted on said cam engaging said slot, and a locking dogholding said pin at either end of the slot. I

3. The combination with a cam shaft of an internal combustion motor, ofa gear wheel mounted thereon and driven from the engine shaft, said gearwheel being provided with an arcuate slot concentric to the cam shaft, acam journa-led on the cam shaft proximate to the side of the gear wheel,a pin mounted on said cam for engaging said slot, a locking means forholding said pin at either end of said slot, and a spring for pressingthe locking means into engaging position.

4. The combination of a cam shaft, a gear journaled on said shaft andhaving an arcuate slot, a cam secured to said shaft and positionedadjacent said gear. a pin on said cam extending into said slot, saidgear also having a pair of depressions in its face cor responding to therelative position of the pin in said arcuate slot, and spring-pressedelements with the pin at the ends of. the slot and adapted to be engagedby said springpressed dog to hold the said pin in the corresponding endof the slot.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing Witnesses, on this 27th day of December AD.1912.

THOMAS \V. MORGAN. \Yitnesses:

H. B. PLUMB,

Ms. M. HUBBARD.

